Densities and Volumetric Properties of Binary Mixtures of Formamide with 1-Butanol, 2-Butanol, 1,3-Butanediol and 1,4-Butanediol at Temperatures between 293.15 and 318.15 K

Abstract

The densities of binary mixtures of formamide (FA) with 1-butanol, 2-butanol, 1,3-butanediol, and 1,4-butanediol, including those of the pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, VmE, partial molar volumes, \(\smash{\overline V _{m,1}^\circ }\) and \(\smash{\overline V _{m,2}^\circ }\), at infinite dilution, and excess partial molar volumes, \(\smash{\overline V _{m,1}^{\circ {\rm E}}}\) and \(\smash{\overline V _{m,2}^{\circ {\rm E}}}\), at infinite dilution were calculated. The variation of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions in these mixtures. The partial molar expansivities, \(\smash{\overline E _1^\circ}\) and \(\smash{\overline E _2^\circ}\), at infinite dilution and excess partial molar expansivities, \(\smash{\overline E _1^{\circ {\rm E}}}\) and \(\smash{\overline E _2^{\circ {\rm E}}}\), at infinite dilution were also calculated. The VmE values were found to be positive for all the mixtures at each temperature studied, except for FA + 1-butanol which exhibits a sigmoid trend wherein VmE values change sign from positive to negative as the concentration of FA in the mixture is increased. The VmE values for these mixtures follow the order: 1-butanol < 2-butanol < 1,3-butanediol < 1,4-butanediol. It is observed that the VmE values depend upon the number and position of hydroxyl groups in these alkanol molecules.